The present invention relates generally to a carrying device for a vehicle and more particularly to a spare tire carrier.
Vehicles with inflatable tires are conventionally equipped with spare tires. Some spare tires are stored under the vehicle using a tire carrier which includes a winch for raising and lowering the spare tire between a stowed and a released position. The winch generally raises and lowers the spare tire using a flexible member such as a cable or cord that is wound and unwound around a spool or wheel.
For example, U.S. patent application Ser. No. 09/834,666, published on Oct. 17, 2002 as Pub. No. U.S. 2002/0149008, and issued on Mar. 4, 2003 as U.S. Pat. No. 6,527,252, which is incorporated by reference herein, describes an underbody spare tire storage assembly having a support member including a base, a primary support mechanism, a secondary support mechanism including a cylindrical fitting member, and a release member. The primary support member includes a flexible member in the form of a multi-strand steel cable that may be wound around a rotating drum. One end of the multi-strand steel cable is crimped to the cylindrical fitting member of the support mechanism. This crimped end, in turn, supports the spare tire (the end of the fitting member at which the cable enters the fitting is referred to here as the receiving end of the fitting member). In order to stow the spare tire, the user causes the drum to rotate, thus winding the multi-strand steel cable onto the drum and lifting the spare tire until the multi-strand steel cable is fully wound as per the design requirements. A disadvantage of these known types of spare tire storage systems lies in the connection between the multi-strand steel cable and cylindrical fitting member at the receiving end of the fitting member. Over the service lifetime, and especially when the spare tire is not in a fully tightened position, bending of the multi-strand steel cable can occur at sharp angles at or near its connection to the fitting member at the receiving end of the fitting member. In addition, abrasive surface-to-surface wear between the cable and receiving end of the fitting member can also occur. The repetition of the abrasive wear and sharp bends of the cable can cause cable failure by either fatigue or wear or tensile loading or any combination of these failure modes. This may include fraying and eventual braking of the multi-strand steel cable at the receiving end of the fitting member.
Failure of the flexible member in such a spare tire storage assembly could have the undesirable consequence of allowing the load (i.e. the spare tire) to become detached from the vehicle. For this reason, there have been many attempts to provide a secondary latch mechanism to prevent the load from becoming detached from the vehicle in the case of a failure of the flexible member. U.S. Pat. Nos. 6,267,546, 6,293,522, and 6,142,449 are examples of such safety mechanisms and generally describe support mechanisms for releasably storing a spare tire on a vehicle.
An object of the present invention is to provide a support mechanism for use in releasably storing a load on a vehicle that improves the durability of the flexible member or multi-strand steel cable of the support system. Modifying the geometry of the receiving end of the fitting member decreases wear and therefore also the failure rate of a multi-strand steel cable or other flexible member.
The present invention provides a support mechanism with improved durability performance for use in releasably stowing a load on a vehicle. The support mechanism includes a flexible member extending from the vehicle and an annular fitting member having a receiving end for receiving the flexible member. The flexible member is bendable and may include a multi-strand steel cable. An inside surface of the fitting member is tapered at the receiving end so that an inside diameter of the fitting member decreases with distance from the receiving end. The annular fitting member may also include a swivel portion to allow the load to rotate relative to the flexible member. The support mechanism may include a secondary latch mechanism to as an added safety measure in case of eventual failure of the flexible member or other part of the mechanism.
The support mechanism may also include a fitting member that is crimped to the flexible member at a distance from the receiving end of the fitting member. The tapered inside surface of the fitting member may be curved in a longitudinal direction of the flexible member, i.e. a rounded taper. The taper may extend to the point at which the fitting member is crimped to the flexible member, after which point the inside diameter of the fitting member may be nearly constant as determined by the crimp. Furthermore, the fitting member may be configured to support the load, either directly, or by supporting other members that, in turn, support the load. The load may include a spare tire.
The support mechanism may also include a winding mechanism for selectively winding the flexible member, which may be a metal multi-strand steel cable. The support mechanism may move the load from a stowed to a released position. The support mechanism may also include a support member configured to be supported by the fitting member. The support member defines an aperture for receiving the multi-strand steel cable and has a convex surface in contact with a retainer member that supports the load. The convex surface may be at least partially spherical. The load may include a spare tire assembly having a hub defining a central aperture, and the retainer member may have a configuration that allows it to pass through the central aperture in a released position of the support mechanism.
In addition, the support mechanism may also include a compression member configured to provide compressive force on the fitting member in a stowed position of the support mechanism. Where the load is a spare tire, the compression member may be configured to provide a compressive force on the fitting member in a stowed position of the support mechanism when the tire is deflated. The annular fitting member may include a flange for supporting the compression member.
The invention also provides a method for selectively moving a load on a vehicle from a stowed position to a released position (or from a released position to a stowed position) using a supporting mechanism including a flexible member extending from the vehicle. The method includes providing an annular fitting member having a receiving end for receiving the flexible member, supporting the load using the fitting member, and either moving the fitting member further away from the vehicle so as to bring the load into the released position or moving the fitting member closer to the vehicle so as to bring the load into the stowed position. An inside surface of the fitting member is tapered at a region of the receiving end so that an inside diameter of the fitting member decreases with distance from the receiving end. The moving of the fitting member may be performed using a winding mechanism to unwind (or wind) the flexible member.